As a conventional crimp terminal, there is one disclosed in Japanese patent application laid-open publication No. 2009-123623 (patent literature 1). As shown in FIG. 1 and FIG. 2, an electric wire W to which a crimp terminal 110 is connected has a core wire 101 composed of a plurality of strands 101a and an insulating sheath 102 that covers the periphery of the core wire 101. At the tip side of the electric wire W, the insulating sheath 102 is removed to expose the core wire 101.
The crimp terminal 110 has a counterpart terminal connection part 111 and an electric wire connection part 115. The electric wire connection part 115 has a core wire crimping part 116 and a sheath crimping part 117. The core wire crimping part 116 has a bottom part 116a and a pair of caulking piece parts 116b that extend from both sides of the bottom part 116a. Three long grooves (serrations) 118 are formed on the inner surface of the bottom part 116a and the pair of caulking piece parts 116b of the core wire crimping part 116. The long grooves 118 are arranged to have a direction orthogonal to the axial direction of the core wire 101 as their longitudinal direction. The sheath crimping part 117 has a bottom part 117a and a pair of caulking piece parts 117b that extend from both sides of the bottom part 117a. 
The crimp terminal 110 caulkingly crimps the exposed core wire 101 with the core wire crimping part 116 and caulkingly crimps the insulating sheath 102 with the sheath crimping part 117.